Stoker-furnace



J. S. SKELLY.

STOKER FURNACE.

APPLICATION FILED 001216, 1919.

Patented Oct. 18, 1921.

2 SHEETS-SHEET I.

J. s. SKELLY.

STOKER FURNACE. APPL|CATION FILE D OCT. 16.1919.

Patented Oct. 18, 192L- 2 $HEE TSSHEET 2- UNITED STATES PAENT OFFICE,

JOHN S. SKELLY, OF MONONGAHELA, PENNSYLVANIA, ASSIGNOR ENGINEERING GORPORATION, OF NEW YORK.

TO COMBUSTION YORK, N. Y., A. CORPORATION OF NEW STOKER-FURNACE.

Application filed October 16, 1919.

T0 aZZ 10720722 it-mag concern: I

Be it known that I, JOHN S. SKELLY, a citizen of the United States, residing at lilonongahela, \Yashington county, State of Pennsylvania, have invented certain new and useful Improvements in Stoker-Furnaces, of

which the following is a full, clear, and exact descriptlon.

My invention relates to improvements in stoker furnaces and more particularly to Stoker furnaces of the under-feed type and has for its object to provide a stoker in which the partly burned out fuel can be consolidated for the purpose of enabling the complete burning out of the residual coke by preventing the formation of thin spots in the fuel bed. It further has for its 0b ect to provide means for supplying the proper amounts of air for the portions of the uel bed containing fresh fuel and-the portions containing the consolidated partly burned out fuel. It further has for its object to provide means for regulating the degree of consolidation of the partly burned out fuel. It further has for its object to pro Me a stoker in which the major portion may be made of astandard length so that additions of different lengths may be supplied so as to make the total length of the grate from its upper to its lower end whatever may be desired for any given installation.

It further has for its object to provide a stoker in which the parts of the grate most liable to be burned out can be renewed without disturbing other portions of the grate. It further has for its object. to provide a stoker which can handle a wide variety of fuel with better economy and etliciency. It further has for its object to provide a stoker. a grate composed of an upper and lower series of tubular grate bars, one of which extends beyond the other, and means for supplying air to said grate bars independently. It further has for its object to provide means for adjusting the grate bars of one series and their movement relatively to the grate bars of the other series and their movements. It further has for its-object to provide a simple fuel feeding means and connections therefrom for actuating the movable grate bars. The invention is shown in connection with a front feed stoker but its use is not confined to stokcrs of that type.

The following is a description of an em Specification of Letters Patent.

Patented Oct. 18, 1921. Serial No. 330,953. I

bodiment of my invention, reference being had to the accompanying drawings, in which, Figure 1 shows in perspective a section of a Stoker furnace embodying my invention; and

Fig. 2 shows a. vertical section parallel to the axes of the grate bars; 7

- F 1g. 3 shows the details of a modification. Referring more particularly to the drawings, 1 and 2 are the furnace walls of a furnace having a front feed stoker provided With a front retort 3. 4 is a hopper which contains fuel which discharges into the passage 5, extending across the face of the furnace and in which moves a reciprocating pusher 6 causing fuel discharged from the hopper 4: to be forced into the retort 3. From the inner edge of the retort 3 extends aseries of tubular grate bars 7 and 8, the bars '7 being movable and the bars 8 stationary, the movable and stationary bars alternating throughout the extent of the grate in the manner shown in Wood Patent No. 818,010 of Jan. 10, 1906. These grate bars 7 and 8 are provided with inlet and outlet ports on the under sides thereof and located at their upper and lower ends respectively. 9 and 10 are the walls of an air chamber 11 which communicates with the inlet ports 12 of the tubular bars. The wall 10 supports a rocker bar 13 provided with a flange 14 which fits in notches on the under side of the movable grate bars so that when the rocker bar 13 is oscillated the movable grate bars are reciprocated in a manner well understood. Below the body of the grate bars is the air chamber 15 into which the outlet ports 16 of the upper bars discharge and from whence air passes upward through the grate to the coal superimposed thereon, the lower end of the bars being supported by the bar wall 17 of this air chamber. The lower series is made up of movable bars 18 and alternating stationary bars 19, the movable bars 18 being actuated by rocker bars 20 similar to the rocker bars 13 carried by the wall 91 of an air chamber 22 located beneath the body portions of the bars 18 and 19. The rear wall 28 of the chamber 2:2 supports the lower ends of those bars. The walls 17 and 21 form an air passage 2% which connects with inlet ports of the tubular bars 18 and 19, whose outlet ports 26 discharge into the chamber 22 so that the air passing through the bars 18' and 19 is discharged into the chamber 22 and thence passes upward through the series to the superimposed partly consumed fuel. Adjacent-grate bars in both series have air passages between them through which air passes upward from the respective air chambers to the superimposed fuel. The chamhers 11 and 22 are respectively connected to passages 27 and 28 which are in turn connected to the main. passage 29.' The passages 27 and 28 are respectively provided with pivoted dampers 30 and 31 provided with suitable handles and 33 for adjusting the same, while the main passage 29 is provided with a similar damper 34: provided with a handle 35. Beyond the series of grate bars 18 and 19 is an ordinary pivoted ash grate 36 to which is connected a rod 37 extending to the front of the stoker for the purpose of moving the ash grate to and from a-horizontal position.

In order to actuate the plunger 6, 1 provide a lever 38 pivoted at 89 and connected by a link 40 to the plunger 6. Connected to the lever 38 by a link 41 is a piston rod 4-9. within the cylinder 43, which is supplied with suitable fluid under pressure, controlled in the ordinary manner to cause the piston rod 42 to slowly reciprocate and thus reciprocate the pusher 6. In order that the power cylinder 13 may bars 13 and 20, I provide the rocker bar 13 with a crank arm 14;, which is connected by links do, 45 to the lever 38 mounted on the remote end of the shaft 39 so as to in that way transmit motion from the piston rod 42.

4L6, which is con nected by links 47 and 18 with an intermediate lever 49 whose lower end is fulcrumed at 50 and whose upper end is connected to the link 45 by a pin and slot connection as shown, so as to be oscillated by the movement ofthelink 45 and thus transmit motion to the link 47 and rocker bar 20. The lever l9 is provided with a serires of holes, to any one of which the front end of the link 4L8 can be coni'iectcd, thus providing; for the adjustment of that link with a corresponding variation in the amount of throw of the crank arm #16 and ocillation of the rocker bar 20. The lever 38 is also provided with a series of holes to any one of which the link 14-5 can be conneetec so as to adjust the throw of the bars 7. The forward ends of the links and 4-7 are guided by any suitable means so that their movements are substantially horizontal.

As shown in Fig. 2, the movable bars 7 and 18 when they are moved, move simultaneously in the same direction. in Fig. 3 I have shown a, modification whereby the movable bars 7 and 18 can be made to move in opposite directions. In order to accomplish this result, I provide a fixed fulcrum block 51 to which the lever 49 is pivalso actuate the rocker- I also provide the rockerbar 20 with a crank arm mesmeoted at point 52, the link 4:8 being connected tothe lower end of the lever i9 by means of an adjustable connection. By this construction the link 47 will be moved toward the front when the link a5 is movingtoward the rear and the grade bars 7 and 18 will thereby be moving in opposite directions at the same time. By disconnecting the lever 4.9 from the link 45 all the bars of the lower series may be made to remain stationary while bars in the upper series reciprocate.

In the operation of this apparatus coal is placed in the hopper i, from which it is forced into the retort} and thence onto the fire bars 7 and 8. The reciprocation of part of these fire bars causes the fuel to move slowly toward the bridge wall 2-. In its progress down the grate bar it is gradually burned by the air which passes between the bars 7 and 8-. As the fuel approaches the end of the first series of. bars the bed becomes thinner and tends to become more open, allowing an excess amount of air to pass through it. if the bars 7 and 8' are unduly long the fuel bed near its lower end' would be very open and thin and would show numerous air holes or black spots indicating that the fuel was entirely burned out. In my construction the bars 7 and 8 are not so long and this condition can not occur to such a great extent.

The action of the bars 7 and 8 in moving the fuel down forces it onto the second series" of bars 18,- 19. The movement of the bars 18 is variable, so that the progress of the from the chamber 22 between the bars 18, 1

19 and thence through the fuel bed. I provide means for adjusting the movement or reciprocation of the bars 7 in the first series and also of the bars 18 in the second series,

so that the relative movements can be varied 1 over a sufficiently wide range to meet the conditions that occur with different grades of fuel. The control. of air by means of the dampers 30 and 31 enables me to adjust the airpressure under each series of grate bars so as to insure the complete burning out of the fuel before it reaches the dump grate 36 and without forcing unburned fuel over onto the dump grate. It also enables me to completely consume the fuel while on the upper section, in which case the air would be e it off the second section. It'enables me to retard the rate of fuel consumption on The effect of if balance.

With my construction it is possible to provide a stokersection of standard length, comprising the feeding mechanism, the air chambers 11 and 15, the second air compartment which receives air from the duct 28, and means for moving the second series of bars. I can then vary the length of the second series ofw bars 18,19 and the compartment 22, and thus obtain as long a grate as may be desired to fit the particular conditions.

Furthermore, in this type of stoker the lower section is more likely to burn out and with the construction shown in my invention it is possible to renew the bars of the lower series at comparatively small expense without disturbing the balance of the stoker.

As will be evident to those skilled in the art, my invention permits of various modifications without departing from the spirit thereof or the scope of the appended claims.

What I claim is:

1. In a stoker furnace, the combination of two separable series of fuel supporting grate bars arranged on different levels and longitudinally displaced with reference to each other so that the upper series overlaps the other and discharges thereon, adjacent bars in each series having air passages between them, means for reciprocating bars in the upper series, the bars of both series being tubular and provided with inlet and outlet ports, means for supplying air to the inlet ports, and air chambers for receiving air from the outlet ports and discharging said air upwardly through said passages between the adjacent bars of said two series.

2. In a stoker furnace, the combination of two separable series of fuel supporting grate bars arranged on different levels and longitudinally displaced with respect to each other so that the upper series overlaps the other and discharges thereon, adjacent bars having air passages between them, means for reciprocating bars in the upper series, the bars of both series being tubular and provided with inlet and outlet ports, means for supplying air to the inlet ports, air chambers for receiving air from the outlet ports and discharging said air upwardly through said passages between the adjacent bars of said two series, and means for controlling the supply of air to said inlet ports.

- 3. In a stoker furnace, the combination of two separable series of fuel supporting grate bars arranged on different levels and longitudinally displaced so that the upper series overlaps the other and discharges thereon, adjacent bars having air passages between them, means for reciprocating bars in each series, the bars of both series being tubular and provided with inlet and outlet ports, means for supplying air to the inlet ports, air chambers for receiving air from the outlet ports and discharging said air upwardly through the passages between adjacent bars of said two series, and means for controlling the supply of air through said several inlet ports, the means for controlling the supply of air to the inlet ports of the be sof one 79 series being independent of the means for controlling the supply of air to the inlet ports of the bars of the other series.

at. In a stoker furnace, the combination of two separable series of fuel supporting grate bars arranged on different levels and longitudinally displaced so that the upper series overlaps the other and discharges thereon, adjacent bars-having air passages between them, means for reciprocating bars in the 30 upper series, the bars of both series being tubular and provided with inlet and outlet ports, means for supplying air to the inlet ports and air chambers for receiving air from the outlet ports and discharging said 5 air upwardly through said passages between adjacent bars, the inlet ports being located adjacent to the upper ends of the bars of both of said series.

5. In a stoker furnace, the combination of 9 two separable series of fuel supporting grate bars arranged on different levels and longitudinally displaced so that the upper series overlaps the other and dischar es thereon, adjacent bars in each series having air pase5 sages between them, means for reciprocating bars in the upper series, the bars of both series being tubular and provided with iniet and outlet ports, means for supplying air to the inlet ports and air chambers for receiving air from the outlet ports and discharging said air upwardly through said passages between adjacent bars, the bars in the two series being inclined in the same direction.

6. In a stoker furnace, the combination of two separable series of fuel supporting grate bars arranged on different levels and longitudinally displaced so that the upper series overlaps the other and discharges thereon, adjacent bars having air passages between 111) them, means for reciprocating bars in both series, the bars of both series being tubular and provided with inlet and outlet ports, means for supplying air to the inlet ports, air chambers for receiving air from the out 115 let ports and discharging said air upwardly through said passages between. adjacent bars, the inlet ports being located adjacent to the upper ends of the bars of both of said series.

7. In a stoker furnace. the combination of me two separable series of fuel supporting grate bars arranged on different levels and longitudinally displaced so that the upper series overlaps the other and discharges thereon, adjacent bars having air passages between them, means for reciprocating bars in the upper series. the bars of both series being tubular and provided with inlet and outlet ports, means for supplying air to the inlet ports, air chambers for receiving air from ing fuel through said retort j the outlet ports and discharg n said i- Q air upwardly through said passages between adjacent bars, a retort adjacent to the upper ends of the upper series and having an inlet below the level of said upper ends, and means for forcing fuel through said retort inlet.

8; In a stoker furnace, the combination of two separable series or": fuel su 'iporting grate bars arranged on different levels and longitudinally displaced so that the upper series overlaps the other and discharges thereon, adjacent bars having air passages between them, means for reciprocating bars in both series, the bars of both series being tubular and provided with inlet and outlet ports, means for supplying air to the inlet ports, air chambers for receiving air from the outlet ports and discharging said air upwardly through said passages between adjacent bars, a retort adjacent to the upper ends of the upper serles and having an inlet below the and means for forcinlet.

9. In a stoker furnace, the combination of two separable series of fuel supporting grate bars arranged on different levels and longitudinally displaced with reference to each other so that the upper series overlaps the other and discharges thereon, adjacent bars in-each series having air passages between level of said upper ends,

mea re them, means for reciprocating bars in both series, the bars of both series being tubular and provided with inlet and outlet ports, means for supplying air to the inlet ports, air chambers for receiving air from the outlet ports and discharging said air upwardly through said passages between the adjacent bars of said two series, and means for inclependently varying the movements of the movable bars in the two series.

10. In a stoker furnace, the combination of two separable series of fuel supporting grate bars arranged on dilierent levels and longitudinally displaced so that the upper series overlaps the other and discharges thereon, adjacent bars having air passages between them, means for reciprocating bars in both series, the bars of both series being tubular and provided With inlet and outlet ports, means for supplying air to the inlet ports, air chambers for receiving air from the outlet ports and discharging said air upwardly through said passages between adj acent bars, a retort adjacent to the upper ends of the upper series and having an inlet below the level of said upper ends, means for forcing fuel through said retort inlet,'and means for independently varying the movements of the movable bars in the two series.

JOHN S. SKELLY- 

